PHILADELPHIA -- Researchers at the University of Pennsylvania have created low-density aerogels made from carbon nanotubes, CNTs, that are capable of supporting 8,000 times their own weight. The new material also combines the strength and ultra-light, heat-insulating properties of aerogels with the electrical conductivity of nanotubes.

Aerogels are unique, low-density materials created by replacing the liquid component of a gel with gas and are normally constructed from silicon dioxide or other organic polymers. They are currently used as ultra-light structural materials, radiation detectors and thermal insulators. Aerogels made from CNTs offer advantages to current aeroegels that point towards future applications in chemical or biological sensors.

A collaboration led by Arjun G. Yodh and Jay Kikkawa of the department of Physics and Astronomy at Penn created the aerogels by freeze-drying or critical-point-drying CNT networks suspended in fluid. The process produces a carbon nanotube network whose carbon concentration, electrical conductivity and strength can be manipulated. Critical-point-drying demonstrated reproducible conductivity in the aerogels.

The findings were reported in the journal Advanced Materials.

The team also maintained control of the density, microscopic structure and shape of the CNT aerogels, as well as their strength. By adding small amounts of polyvinyl alcohol during processing, very strong aerogels were created. The nanotube dispersion process was optimized to create an even distribution of nanotubes within the aerogel.

The study was conducted by Yodh, Kikkawa, Mateusz B. Bryning, Daniel E. Milkie and Lawrence A. Hough of Penn's Department of Physics and Astronomy and Mohammad F. Islam of the Department of Chemical Engineering at Carnegie Mellon University.

Multimedia

At the fifth annual Philly Robotics Expo (PRX) on April 20, several hundred local grade-, middle-, and high-school students poured into the Singh Center for Nanotechnology with their machines in tow.
Adobe Flash is required to view this content...

Sophia Hu is as fearless on the rugby field as she is in the classroom. “I love rugby because it’s a great way to de-stress from school,” says Hu. “Whatever frustrations I get from school, when I get on the field, I tackle people, I scream at the top of my lungs.”

From Harare, Zimbabwe, Rutendo Chigora is a senior double majoring in international relations and political science, and minoring in English. In December, she was awarded one of the two Rhodes Scholarships available to students from Zimbabwe. She will study at the University of Oxford in Oxford,...